Air intake streams to engines for motorized vehicles, power generation equipment and similar equipment generally need to be filtered, for protection of the engine equipment from particulates carried in the air streams. In general, air filter arrangements are utilized upstream of the engine, with respect to air flow, for such filtering.
In some systems it is desirable to remove particulate material from air flow streams for other reasons, such as aesthetics or personal health and comfort. For example, cabin air filter systems for vehicles such as large agricultural tractors, mobile homes and automobiles, serve this purpose.
In general, principal areas of design focus with respect to such filter arrangements include: accommodating space limitations; achieving desired levels of filtering efficiency; and, obtaining preferred lifetime of use. It is generally desirable to provide for relatively long life or extended life filter arrangements, so that frequent removal and replacement of filter elements is avoided. However, it is generally preferred to obtain that long life without substantial loss of efficiency.